Substituted 5-(ortho carboxanilidophenoxymethyl)tetrazoles

ABSTRACT

SUBSTITUTED TETRAZOLES WHICH ARE USEFUL FOR THE TREATMENT OF INFLAMMATORY DISORDERS IN MAMMALS ARE PROVIDED HAVING THE GENERAL FORMULA   1-((1H-TETRAZOL-5-YL)-CH2-O-),((R2,R3-PHENYL)-NH-CO-),   R1-BENZENE   IN WHICH R1, R2 AND R3 EACH REPRESENT HYDROGEN, ALKYL CONTAINING UP TO SIX CARBON ATOMS, ALKOXY CONTAINING UP TO SIX CARBON ATOMS, HALOGEN OR TRIFFLUOROMETHYL.

United States Patent 3,649,637 SUBSTITUTED S-(ORTHO CARBOXANILIDO- PHENOXYMETHYDTETRAZOLES John Gordon Bernard Howes, Hertford, and Rupert Aleck Selway, Harlow, Essex, England, assignors to T. J. Smith & Nephew Limited, Kingston-upon-Hull, England No Drawing. Filed Nov. 4, 1968, Ser. No. 773,306 Claims priority, application Great Britain, Nov. 3, 1967, 50,066/67 Int. Cl. A61k 27/00; C07d 55/56 US. Cl. 260-308 D 4 Claims ABSTRACT OF THE DISCLOSURE Substituted tetrazoles which are useful for the treatment of inflammatory disorders in mammals are provided having the general formula in which R R and R each represent hydrogen, alkyl containing up to six carbon atoms, alkoxy containing up to six carbon atoms, halogen or trifiuoromethyl.

Processes for the preparation of the substituted tetrazoles are also provided together with intermediates for use in their preparation.

This invention relates to substituted tetrazoles and to processes for their preparation.

According to the invention substituted tetrazoles are provided having the general formula:

in which R R and R each represent hydrogen, alkyl containing up to six carbon atoms, alkoxy containing up to six carbon atoms, halogen or trifluoromethyl.

The invention includes a process for the preparation of the compounds of general Formula I by reacting a substituted carboxanilido phenoxyacetonitrile having the general formula:

0 CHzCN wherein R R and R have the meanings given above with an azide such as for example ammonium azide.

The phenoxyacetonitriles of Formula II, which are novel compounds, may be prepared for example by the 3,649,637 Patented Mar. 14, 1972 ice reaction of chloroacetonitrile with a substituted salicylanilide having the general formula:'

in the presence of an alkali metal carbonate, hydroxide or alkoxide.

The invention also includes a process for the preparation of the compounds of general Formula I by the reaction of a tetrazolo (5,1-c)2,3,4,5-tetrahydro-1,4-benzoxazepin-S-one having the general formula:

III

with an aniline of the general formula N Hz R i R3 V wherein R R and R have the meanings given above.

The tetrazolo (5,1-c)2,3,4,5-tetrahydro1,4-benzoxazepin-S-ones of Formula IV, which are novel compounds, may be prepared by the treatment of 5-(2-carboxy-phenoxymethyl)-tetrazoles of general formula:

EXAMPLE I 5- 2- 4-methylphenylcarbamoyl -4-chlorophenoxymethyl] -tetrazole 2-(4-methylphenylcarbamoyl-4-chlorophenoxy acetonitrile (see Preparation I below) (8.00 grams:0.0266 mole), sodium azide (2.02 g.; 0.031 mole) and ammonium chloride (1.68 g.; 0.031 mole) were added to N,N-dimethylformamide (40 ml.) and heated with stirring on a steam bath for 18 hours. The solvent was removed under reduced pressure, and the residual oil dissolved in ammonium hydroxide (150 ml.; 1.5 N). The solution was extracted three times with ethyl acetate before acidifying to pH 2 with dilute hydrochloric acid. The precipitated product Was filtered, washed with water and dried to give material M.P. 178-179" C. (7.76 g.; 85%).

Recrystallisation from N,N-dirnethylformamide:water (1:2 v./v.) gave the tetrazole as white needles M.P. 191- 192 C.

C I-I C1N O .-Requires (percent): C, 55.90; H, 4,10; N, 20.37. Found (percent): C, 55.96; H, 4.11; N, 20.11.

The following compounds were prepared from appropriately substituted intermediates by a method similar to Example 1.

EXAMPLE II 5- [2- (4-chlorophenylcarbamoyl) -4- chlorophen oxymethyl] -tetrazole White needles from N,N dimethylformamidezwater (1:2 v./v.) M.P. 187-188 C.

C H Cl N O .-Requires (percent): C, 49.46; H, 3.04; N, 19.23. Found (percent): C, 49.60; H, 3.12; N, 18.95.

EXAMPLE III 5- [2- 3,4-dichlorophenylcarbamoyl) -phenoxymethyl] -tetrazole White needles from N,N-dimethylformamide:water (1:2 v./v.) M.P. 196-197 C.

C H Cl N O .Requires (percent): C, 49.46; H, 3.04; N, 19.23. Found (percent): C, 49.28; H, 2.99; N, 19.40.

EXAMPLE IV 5- (2-phenylcarbamoyl -phenoxymethyl] -tetrazo1e IWhite rods from N,N-dimethy1formamide: water (1:2 v./v.) M.P. 167-168 C.

C H N O .-Found (percent): C, 61.14; H, 4.31; N, 23.82. Requires (percent): C, 61.01; H, 4.44; N, 23.72.

EXAMPLE V 5 [2- (3 -trifluoromethylphenyl carbamoyl -phenoxymethyH-tetrazole 'White micro crystals from acetone:water (1:2 v./v.) M.P. 182-183 C.

C H F N O .-Found (percent): C, 52.83; H, 3.13; N, 18.99. Requires (percent): C, 52.89; H, 3.33; N, 19.28.

EXAMPLE VI 5- [2- (4-ch1orophenylcarbamoyl) -phenoxymethyl] tetrazole White micro crystals from acetone:water (1:2 v./v.) M.P. 213-214 C.

C H ClN O .Found (percent): C, 54.88; H, 3.62; N, 20.99. Requires (percent): C, 54.63; H, 3.67; N, 21.24.

EXAMPLE VII 5-[2-(4-methoxyphenylcarbarnoyl)-phenoxymethyl]- tetrazole 5-[2-(3,4-dichloropheny1carbamoyl)-4-chlorophenoxymethyl] -tetrazole White crystalline solid from N,N-dirnethylformamide: water (1:2 v./v.) M.P. 220-223 C.

C H Cl N O .-Found (percent): C, 45.29; H, 2.45; N, 17.39. Requires (percent): C, 45.19; H, 2.53; N, 17.57.

4 EXAMPLE IX 5 [2- (4-methoxyphenylcarbamoyl) -4-chlorophenoxymethyl]-tetrazo1e White crystalline solid from N,N-dimethy1formamide: Water (1:2 v./v.) M.P. 185-186 C.

C H ClN O .-Found (percent): C, 53.16; H, 3.87; N, 19.36. Requires (percent): C, 53.41; H, 3.92; N, 19.47.

EXAMPLE X 5-[2-(3,4-dichlorophenylcarbamoyl)-4-methy1phenoxymethyl]-tetr-azole White micro needles from acetonezwater 1:2 v./v.) M.P. 212-213 C.

C H Cl N O .-Found (percent): C, 50.51; H, 3.38; N, 18.74. Requires (percent): C, 50.81; H, 3.46; N, 18.52.

EXAMPLE XI 5- [2-(3-trifiuoromethylphenylcarbamoyl)-4-methylphenoxylmethyl] -tetrazole White micro crystals from N,N-dimethylformamide: water (1:2 v./v.) M.P. 188-189 C.

C H .,F N O .Found (percent): C, 54.29; H, 3.99; N, 18.30. Requires (percent): C, 54.11; H, 3.74; N, 18.56.

EXAMPLE XII 5- [2- 3-trifluoromethylphenylcarbamoyl) -4-chlorophenoxymethyl] -tetrazole White micro needles from acetonezwater (1:2 v./v.) M.P. 212-213 C.

C H ClF N O .Found (percent): C, 48.04; H, 2.56; N, 17.74. Requires (percent): C, 48.31; H, 2.79; N, 17.61.

EXAMPLE X111 5 [2- (3 ,4-dich1oro phenylcarbamoyl -5 -methoxyphenoxymethyl] -tetrazole White micro needles from acetonezwater (1:2 v./v.) M.P. 199-200 C.

C H Cl N O .Found (percent): C, 49.00; H, 3.54; N, 17.60. Requires (percent): C, 47.74; H, 3.32; N, 17.77.

EXAMPLE XIV 5-(2- (phenylcarbamoyl)-4-chlorophenoxymethyl)- tetrazole White micro crystals from acetone:water (1:2 v./v.) M.P. 188-189 C.,

C H ClN O .-Found (percent): C, 54.38; H, 3.81; N, 21.03. Requires (percent): C, 54.63; H, 3.66; N, 21.24.

EXAMPLE XV 5-(2-(phenylcarbamyl)-4-methylphenoxymethyl)- tetrazole White micro crystals from acetone:water (1:2 v./v.) M.P. -171 C.

C H N O .-Found (percent): C, 62.03; H, 4.81; N, 23.00. Requires (percent): C, 62.12; H, 4.89; N, 22.64.

EXAMPLE XVI 5- 2- 3 ,4-dichlorophenylcarbamoyl) -4-ethy1phenoxymethyl)-tetrazole White micro crystals from N,N-dimethyl form-amide: Water (1:2 v./v.) M.P. 212-213 C.

C H C1 N O .-Found (percent): C, 51.78; H, 3.70; N, 18.12. Requires (percent): C, 52.05; H, 3.85; N, 17.86.

EXAMPLE XVII 5 (2 (4- chlorophenylcarbamoyl) -4-methylphenoxymethyl) -tetrazole White micro crystals from acetone2water (1:2 v./v.) M.P. 193-194 C.

C H ClN O .-Found (percent): C, 55.63; H, 4.07; N, 20.22. Requires (percent): C, 55.90; H, 4.11; N, 20.37.

EXAMPLE XVIII 5- (2-(3-trichloromethylphenylcarbamoyl) -4-bromophenoxymethyl -tetrazole EXAMPLE XX 5- (2- 3 ,5 -dichlorophenylcarbamoyl -phenoxymethyl)- tetarazole Tetrazolo (5,1-c)2,3,4,5 tetrahydro-1,4-benzoxazepin- 5-one (10.00 g.; 0.0495 mole) was suspended in xylene (100 ml.) and warmed with stirring to 55 C. 3,5-dichloroaniline (8.16 g.; 0.0504 mole) was added in one go and the temperature raised to 100 C. and maintained for 2 hours. The solvent was removed under vacuum to leave a brown solid which was washed well with dilute hydrochloric acid, water, and dried to give material M.P. 213-214 C. (14.18 g.; 80%). Crystallisation from acetone:water (1:2 v./v.) gave the tetrazole as white needles M.P. 220221 C.

C H Cl N O .Found (percent): C, 49.47; H, 3.05; N, 19.23. Requires (percent): C, 49.35; H, 3.28; N, 19.42.

The following compounds were prepared from appropriately substituted intermediates by a method similar to Example XX.

EXAMPLE XXI 5- 2- 3 ,5 -dichlorophenylcarbamoyl) -4- (chlorophenoxymethyD-tetrazole White crystalline solid from acetonezwater (1:2 v./v.) M.P. 226227 C C H Cl N O .Found (percent): C, 45.29; H, 2.45; N, 17.39. Requires (percent): C, 45.19; H, 2.52; N, 17.57.

EXAMPLE XXII 5 (2- (3 -trichloromethylphenylcarbamoyl) -5 (methoxyphenoxymethyl) Needles from acetone:water (2:1 v./v.) M.P. 218 220 C.

C 7H 4F N O3.-FOllI1d (percent): C, 51.83; H, 3.59; N, 17.59. Requires (percent): C, 51.91; H, 3.59; N, 17.80.

Other compounds which have been described above in Examples V, VI, VIII, X and XII and which have been prepared by the method of Example XX are:

EXAMPLE XXIII (For the compound of Example V) 5- (2- (3-t1'ichloromethylphenylcarbamoyl) -phenoxymethyl -tetrazole White micro crystals from acetonezwater (1:2 v./v.) M.P. 182183 C. The yield was 78%.

EXAMPLE XXIV (For the compound of Example VI) 5-(2-(4-chlorophenylcarbamoyl) -phenoxymethyl)- tetrazole White micro crystals from acetonezwater (1:2 v./v.) M.P. 213-214" C. The yield was EXAMPLE XXV (For the compound of Example VIII) 5-(2-(3,4-dichlorophenylcarbamoyl) -4-chlorophenoxymethyl) -tetrazole White crystalline solid from acetonezwater (1:2 v./v.) M.P. 220-223 C. The yield was 91%.

EXAMPLE XXVI (For the compound of Example X) 5- (2- 3 ,4-dichlorophenylcarbamoyl -4-methylphenoxymethyl) -tetrazole White micro needles from acetonezwater (1:2 v./v.) The yield was 99% and the melting point 209-211 C.

EXAMPLE XXVII (For the compound of Example XII) 5 2-3-trichloromethylphenylcarbamoyl -4-chlorophenoxymethyl -tetrazole White micro needles from acetonezwater 1:2 v./v.) The yield was 86% and the melting point 210211 C.

The preparations of the intermediates, which have not previously been described in the literature, are given below.

PREPARATION 1 2-(4-methylphenylcarbamoyl)-4-chlorophenoxyacetonitrile 5-chloro-p-salicylotoluidide (H. W. Hirwe, G. V. Jadhav and D. R. Suktankar, J. Indian Chem. Soc. 16, 281-284 (1939)) (8.24 g.; 0.315 mole), chloro-acetonitrile (3.40 g.; 0.45 mole) and anhydrous potassium carbonate (4.40 g.; 0.316 mole) were added to acetone (80 ml.) and the mixture stirred and refluxed for 20 hours. The mixture was cooled and poured into dilute sodium hydroxide solution (500 ml.; LON). The precipitated product was filtered, washed with water and dried to give material M.P. 127-128 C. (9.14 g.; 96%).

Recrystallisation from actonezwater 1:1 v./v.) gave the nitrile as a white crystalline solid M.P. 142-143 C.

C H ClN O .-Found (percent): C, 64.06; H, 4.26; N, 9.32. Requires (percent): C, 63.90; H, 4.36; N, 9.32.

The following compounds were prepared from appropriately substituted intermediates by a similar method.

PREPARATION 2 2-(4-chlorophenylcarbamoyl)-4-chlorophenoxyacetonitrile White micro crystalline solid from acetonezwater (1:1 v./v.) M.P. -141 C.

C H Cl N O .Found (percent): C, 53.36; H, 3.15; N, 8.99. Requires (percent): C, 56.09; H, 3.14; N, 8.72.

PREPARATION 3 2-(3,4-dichlorophenylcarbamoyl)-phenoxyacetonitrile White micro needles from acetone:water 1:1 v./v.) M.P. 146-147 C.

C15H1oCI2N202.FOuIld (percent): C, H, N, 8.93. Requires (percent): C, 56.09; H, 3.14; N, 8.72.

PREPARATION 4 2-phenylcarbamoyl-phenoxyacetonitrile White needles from ethanol:60/80 petroleum ether (1:1v./v.)M.P.155-l56 C.

C H N O .--Found (percent): C, 71.61; H, 4.72; N, 10.93. Requires (percent): C, 71.41; H, 4.80; N, 11.11.

7 PREPARATION s 2- 3-trifluor0methylphenylcarb arnoyl -phenoxyacetonitrile White micro needles from acetonezwater (1:1 v./v.) M.P.131132 C.

C H F N O .Fund (percent): C, 60.30; H, 3.71; N, 8.94. Requires (percent): C, 60.00; N, 3.46; N, 8.75.

PREPARATION 6 2- (4-chlorophenylcarbamoyl) -phenoxyacetonitrile White needles from acet0ne:water (1:1 v./v.) M.P. 118-119 C.

C H ClN O .Found (percent): C, 62.53; H, 4.03; N, 9.81. Requires (percent): C, 62.83; H, 3.98; N, 9.77.

PREPARATION 7 2- (4-methoxyphenylcarb amoyl) -phenoxyacetonitn'le White crystalline solid from acetone:water (1:1 v./v.) M.P. 100-101 C.

C H N O .Found (percent): C, 67.96; H, 4.84; N, 10.13. Requires (percent): C, 68.07; H, 5.00; N, 9.92.

PREPARATION 8 2-(3,4-dichlorophenylcarbamoyl)-4-chlorophenoxyacetonitrile White needles from acetone:water (1:1 v./v.) M.P. 153-154 C.

C H Cl N O .-Found (percent): C, 50.55; H, 2.58; N, 7.88. Requires (percent): C, 50.66; H, 2.55; N, 7.88.

PREPARATION 9 2-(4-methoxyphenylcarbamoyl)-4-chlorophenoxyacetonitrile White needles from actonezwater (1:1 v./v.) M.P.

C H ClN O .-Found (percent): C, 60.88; H, 3.85; N, 8.81. Requires (percent): C, 60.67; H, 4.14; N, 8.85.

PREPARATION 10 2-( 3,4-dichlorophenylcarbamboyl) -4-methylphenoxyacetonitrile White needles from ethylalcoholz60/80 petroleum ether (1:1 v./v.) M.P. 141142 C.

C H Cl N O .Found (percent): C, 57.62; H, 3.61; N, 8.66. Requires (percent): C, 57.22; H, 3.61; N, 8.36.

PREPARATION 11 1- (3 -trichlorornethylphenylcarh amoyl) -4-methylphenoxy acetonitrile White crystalline solid from acetonezwater (1:1 v./v.)

M.P. 129-130 C.

C H F N O .-Found (percent: C, 61.22; H, 3.85; N, 8.51. Requires (percent): C, 61.08; H, 3.92; N, 8.38.

PREPARATION 12 2- 3 -trifluoromethylphe nylcarb amoyl) -4- chlorophenoxyacetonitrile White feathers from acetone:water (1:1 v./v.) M.P.

C H ClF N O .-Found (percent): C, 54.14; H. 2.57; N, 8.15. Requires (percent): C, 54.17; H, 2.84; N, 7.90.

PREPARATION 13 2- (3 ,4-dichlorophenylcarb amoyl -5- methoxyphenoxyacetonitrile White rods from acetonezwater (1:1 v./v.) M.P. 16l- 162 C.

8 C H Cl N O .Found (percent): C, 54.52; H, 3.67; N, 8.14. Requires (percent): C, 54.72; H, 3.44; N, 7.98.

PREPARATION 14 Z-(phenylcarbamoyl)-4-chlorophenoxyacetonitrile White needles from acetonezwater (1:1 v./v.) M.P. 116-117 C.

C H ClN O .-Found (percent): C, 62.53; H, 3.91; N, 9.93. Requires (percent): C, 62.83; H, 3.87; N, 9.77.

PREPARATION 15 2- phenylcarbarnoyl -4-methylphenoxyacetonitrile White crystalline solid from acetone1water (1:1 v./v.) M.P. 182-183 C.

C H N O .Found (percent): C, 72.17; H, 5.25; N, 10.57. Requires (percent): C, 72.16; H, 5.30; N,

C17H14Cl2H202. -FOHI1(I (percent): C, 58.09; H, 3.84; N, 8.14. Requires (percent): C, 58.47; H, 4.04; N, 8.02.

PREPARATION 17 2-(4-chlorophenyl-carbamoyl)-4-ethylphenoxyacetonitrile White needles from acetone:water (1:1 v./v.) M.P. 133-134 C.

C H ClN O .-Found (percent): C, H, N, 9.50. Requires (percent): C, 63.89; H, 4.36; N, 9.32.

PREPARATION 18 2- (3-trifiuoromethylphenylcarbamoyl -4- bromophenoxyacetonitrile White needles from glacial acetic acid:water (2:1 -v./v.) M.P. 143-144 C.

C H BrF N O .Found (percent): C, 47.89; H, 2.75; N, 7.37. Requires (percent): C, 48.13; N, 2.53; N, 7.02.

PREPARATION 19 2- (phenylcarh amoyl) -4-bromophenoxyacetonitrile White needles from glacial acetic acid M.P. 133-134" C H BrN O .Found (percent): C, 54.51; H, 3.43; N, 8.61. Requires (percent): C, 54.40; H, 3.35; N, 8.46.

PREPARATION 20 (This intermediate was used in Examples XX, XXIII, and XXIV) Tetrazolo-(5,1-c)2,3,4,5-tetrahydro-l,4- benzoxazepin-S-one- 5 (2 carboxyphenoxymethyl) tetrazole (44 g.; 0.20 mole) was treated with thionyl chloride (82 g.; 0.69 mole) in the cold containing 2 drops of N,N-dimethyl formamide. After 1 hour the mixture was slowly warmed to reflux and maintained at this temperature for 2 hours. The excess thionyl chloride was removed to give a brown solid (31.2 g.; 78%). M.P. 128-133 C. decomp. Crystallisation from benzene gave material of M.P. -136 C. decornp.

C H N O .F0und (percent): C, 53.16; H, 2.94; N, 27.54. Requires (percent): C, 53.46; H, 2.99; N, 27.72.

The following compounds were prepared from the appropriately substituted intermediates by a similar method:

9 PREPARATION 21 (This intermediate was used in Examples XXI, XXV and XXVII) 7-chloro-tetrazolo-(5,l-c) 2,3,4,5-tetrahydro-1,4-

benzoxazepin-S-one White needles from acetone M.P. 191-192 C. C H ClN O .-Found (percent): C, 45.91; H, 2.35; N, 23.88. Requires (percent): C, 45.68; H, 2.13; N, 23.68.

PREPARATION 22 (This intermediate was used in Example XXVI) 7-methyl-tetrazolo (5 l-c) 2,3,4,5-tetrahydro-1,4-

benzoxazepin-S-one Colourless rods from acetone M.P. 174175 C. C H N O .Found (percent): C, 55.82; H, 3.85; N, 25.74. Requires (percent): C, 55.55; H, 3.73; N, 25.92.

PREPARATION 23 (This intermediate was used in Example XXII) 8-methoxy-tetrazo1o- 5 1-c) 2,'3,4,5-tetrahydro-1,4-

benzoxazepin-S-one Pale yellow needles from benzene M.P. 186187 C. C H N O .Found (percent): 51.77; H, 3.53; N, 24.28. Requires (percent): C, 51.72; H, 3.47; N, 24.13.

PREPARATION 24 (This intermediate was used in Example XX) 5- (Z-carboxyphenoxymethyl) -tetrazole 5 (2 (phenylcarbamoyl) phenoxymethyl)-tetrazole (8.55 g.; 0.029 mole) was dissolved in 20% sodium hydroxide solution (75 ml.) and refluxed for 5 hours. The cooled solution was extracted with ethylacetate (2X 50 ml.) and then carefully acidified to pH 2 with concentrated hydrochloric acid to precipitate a white solid. The solid was filtered, washed with water and dried to give material M.P. 201-202 C. (5.76 g.; 90%).

Crystallisation from acetonerwater (1:1 v./v.) gave a white crystalline solid M.P. 204-205 C.

C H N O .Fund (percent): C, 51.77; H, 3.53; N, 25.22. Requires (percent): C, 49.09; H, 3.66; N, 25.45.

The following compounds were prepared from appropriately substituted intermediates by a similar method:

PREPARATION 25 (This compound was used in Preparation 21) (Z-carboxy-4-chlorophenoxymethyl) -tetrazole Prepared from 5-[2-(phenylcarbamoyl)-4-ch1orophenoxymethyl]-tetrazole.

White needles from acetone M.P. 210-211 C.

C H ClN O .Found (percent): C, 42.18; H, 2.95; N, 22.31. Requires (percent): C, 42.45; H, 2.77; N, 22.01.

PREPARATION 26- (This compound was used in Preparation 22) 5-(2-carboxy-4-methylphenoxymethyl)-tetrazo1e Prepared from '5-[2-(phenylcarbamoyl) 4 methylphenoxymethyl] -tetrazole.

White micro-needles from N,N-dimethyl formamide: water (1:2 v./v.) M.P. 188189 C.

C H N O .--Found (percent): C, 51.37; H, 4.15; N, 24.13. Requires (percent): C, 51.28; H, 4.30; N, 23.92.

PREPARATION 27 (This compound was used in Preparation 23) 5- 2-carboxy-S-methoxyphenoxymethyl) -tetrazole Prepared from 5-[2-(3,4-dichlorophenylcarbomoyl)-5- methoxyphenoxymethyl] -tetrazole.

White crystalline solid from N,N-dimethyl formamide: water (1:2 v./v.) M.P. 220-221 C.

C H N O .-Found (percent): C, 48.06; H, 4.08; N, 22.15. Requires (percent): C, 48.00; H, 4.02; N, 22.39.

The analgesic and anti-inflammatory efiects of the compounds of \general Formula I are shown by the following experiments in comparison with the known drugs aspirin and phenylbutazone.

1) Phenylbenzoquinone induced writhing in mice. Mice injected with phenylbenzoquinone display a characteristic writhing syndrome which may be prevented by the prior administration of analgesic and anti-inflammatory drugs. The activity of the compound is expressed as an ED i.e. that dose which causes a 50% reduction in writhing frequency.

Compound of Example No. ED (mg/kg. orally) I (2) Carageenin foot oedema in rats-Carageenin inected in the hind paw of rats causes swelling of the paw which may be measured volumetrically. Anti-inflammatory drugs reduce the degree of swelling. The activity is expressed as a percentage reduction of swelling compared with control animals.

Inhibition Compound of Dose (mg./ of swelling, Example N 0. kg. orally) percent eaeaeaeeeaaeaaaeeeaeeeesea esaeea'sasoeeeaeoaaeeea a The preferred compound of general Formula I for use in the treatment of inflammatory disorders are those in which R R and R each represent hydrogen, halogen 75 or trifluoromethyl and especially 5[2-(3,4-dichlorophenyl- 1 1 1 2 carbamoyl)-phenoxymethyl]-tetrazole and 5-[2-(3-trifluo- 2. A compound of claim 1 wherein R R and R each romethylphenylcarbamoyl) 4 chlorophenoxy-methyflrepresent hydrogen, halogen or trifiuoromethvl. tetrazole. 3. 5-[2-(3,4 dichlorophenylcarbamoyl) phenoxy- We claim: methyl] -tetrazole.

1. A compound of the formula: 5 4. 5-[2-'(3-trichloromethylphenylcarba-moyl) 4 ch1o H rophenoxymethyl]-tetrazo1e. N N

References Cited OCHZC R a \N N 10 UNITED STATES PATENTS l CONE-@112 2,977,372 3/ 1961 Finnegan et a1. 7- 0308 ALTON D. ROLLINS, Primary Examiner in which R R and R each represents hydrogen, alkyl 15 U 5 Q X R containing up to six carbon atoms, alkoxy containing up to six carbon atoms, halogen or trifiuoromethyl. 260-239.3 T, 465 D, 559 S; 424-244 

